Older children who are exposed to only small amounts of adult speech are known to be at risk for language delay. A new study in the March 2014 Pediatrics examined whether the same is true for preterm infants.

Researchers used a Language Environment Analysis (LENA) digital recording device to record adults talking to 36 preterm infants at age 32 weeks, and again at age 36 weeks. Every increase by 100 adult words per hour during the recording at age 32 weeks resulted in a 2-point increase in language composite scores at 18 months, and a 0.5-point increase in expressive communication scores. For every 100 adult words per hour at age 36 weeks, there was an increase of 1.2 points in the Bayley Cognitive Composite at 7 months, and an increase of 0.3 points in expressive communication scores at 18 months. At 7 months, the cumulative adult word count for all recordings was associated with higher cognitive and language composite scores, and receptive communication scores. For 18-month outcomes, adult word counts for all recordings were linked to higher expressive communication scores.

Study authors conclude that infants being cared for in the NICU benefit from exposure to adult talk, resulting in both higher language and cognitive scores later in life. Parents should be encouraged to talk to their preterm babies while in the NICU to avoid risk of language delay.